Jul 172014
 

You can pick your friends, but not your family, they say…and it turns out that we pick friends who are like our family. Our friends are likely to be surprisingly genetically similar to us, a new study shows.

There was disturbing evidence that couples with daughters are more likely to divorce. Could it be the girls fault? There’s a surprising twist to this research. It may be that girls are better able, even in the womb, to survive a difficult relationship.

And the stereotype that women like to talk more than men may not be right either. Research suggests that it all depends on the context.

Multitasking – it’s attractive to think we can deal with interruptions, but can we have your complete attention while we discuss the new research? Which unsurprisingly says interruptions affect the quality of our work.

And exercise – it may be the secret to getting a good education. Gym going students do better, a study shows.

And moderate to intense activity reduces the risk of death in older women.

 

Jul 162014
 

Woman talking on phone at deskWe’ve all heard the stereo­type: Women like to talk, Angela Herring writes. We bounce ideas off each other about every­thing from career moves to dinner plans. We hash out big deci­sions through our con­ver­sa­tions with one another and work through our emo­tions with discussion.

At least, that’s what “they” say. But is any of it actu­ally true? Can we really make such sweeping gen­er­al­iza­tions about the com­mu­ni­ca­tion pat­terns of women versus those of men? The research is sur­pris­ingly thin con­sid­ering the strength of the stereo­type: Some studies say yes, women are more talk­a­tive than men. Others say there’s no pat­tern at all. Still others say men are even bigger chatterboxes.

Per­haps all this con­tra­dic­tion comes from the dif­fi­culty of studying such a phe­nom­enon. Most of these studies rely on either self-​​reported data, in which researchers gather infor­ma­tion by asking sub­jects about their past con­ver­sa­tional exploits, or obser­va­tional data, in which researchers watch the inter­ac­tions directly. But both of these approaches bring with them some hefty lim­i­ta­tions. For one thing, our mem­o­ries are not nearly as good as we like to think they are. Sec­ondly, researchers can only observe so many people at once, meaning large data sets, which offer the most sta­tis­tical power to detect dif­fer­ences, are hard to come by. Another chal­lenge with direct obser­va­tion is that sub­jects may act in a more affil­ia­tive manner in front of a researcher.

But a new study from North­eastern pro­fessor David Lazer, who researches social net­works and holds joint appoint­ments in the Depart­ment of Polit­ical Sci­ence and the Col­lege of Com­puter and Infor­ma­tion Sci­ences, takes a dif­ferent approach. Using so-​​called “sociometers”—wearable devices roughly the size of smart­phones that col­lect real-​​time data about the user’s social interactions—Lazer’s team was able to tease out a more accu­rate pic­ture of the talkative-​​woman stereo­type we’re so familiar with—and they found that con­text plays a large role.

The research was pub­lished Tuesday in the journal Sci­en­tific Reports and rep­re­sents one of the first aca­d­emic papers to use sociome­ters to address this kind of question. The research team includes Jukka-​​Pekka Onnela, who pre­vi­ously worked in Lazer’s lab and is now at the Har­vard School of Public Health, as well as researchers at the MIT Media Lab­o­ra­tory and the Har­vard Kennedy School.

For their study, the research team pro­vided a group of men and women with sociome­ters and split them in two dif­ferent social set­tings for a total of 12 hours. In the first set­ting, master’s degree can­di­dates were asked to com­plete an indi­vidual project, about which they were free to con­verse with one another for the dura­tion of a 12-​​hour day. In the second set­ting, employees at a call-​​center in a major U.S. banking firm wore the sociome­ters during 12 one-​​hour lunch breaks with no des­ig­nated task.

In the one set­ting that is more col­lab­o­ra­tive we see the women choosing to work together, and when you work together you tend to talk more,” said Lazer, who is also co-​​director of the NULab for Texts, Maps, and Net­works, Northeastern’s research-​​based center for dig­ital human­i­ties and com­pu­ta­tional social sci­ence. “So it’s a very par­tic­ular sce­nario that leads to more inter­ac­tions. The real story here is there’s an inter­play between the set­ting and gender which cre­ated this difference.”

Source: Northeastern University

Jul 162014
 

Pregnancy - pregnant woman family issueIn the U.S., couples with daughters are somewhat more likely to divorce than couples with sons. Many scholars have read those numbers as evidence that daughters cause divorce.

But new research from Duke University suggests something quite different may be at play: Girls may be hardier than boys, even in the womb, and may be better able to survive pregnancies stressed by a troubled marriage.

Previous studies have argued that fathers prefer boys and are more likely to stay in marriages that produce sons. Conversely, the argument runs, men are more likely to leave a marriage that produces daughters. That scholarly claim has been around for decades, and has gained a following in popular culture.

“Many have suggested that girls have a negative effect on the stability of their parents’ union,” said Duke economist Amar Hamoudi, who co-authored the new study with Jenna Nobles, a University of Wisconsin-Madison sociologist. “We are saying: ‘Not so fast.’ “

Their study appears online July 15 in the journal Demography.

Hamoudi, who teaches in Duke’s Sanford School of Public Policy and is a fellow of the Duke Center for Child and Family Policy, points to a very different potential explanation for differing divorce rates: the robustness of female embryos.

Throughout the life course, girls and women are generally hardier than boys and men. At every age from birth to age 100, boys and men die in greater proportions than girls and women. Epidemiological evidence also suggests that the female survival advantage actually begins in utero. These more robust female embryos may be better able to withstand stresses to pregnancy, the new paper argues, including stresses caused by relationship conflict.

Based on an analysis of longitudinal data from a nationally representative sample of U.S. residents from 1979 to 2010, Hamoudi and Nobles say a couple’s level of relationship conflict predicts their likelihood of subsequent divorce.

Strikingly, the authors also found that a couple’s level of relationship conflict at a given time also predicted the sex of children born to that couple at later points in time. Women who reported higher levels of marital conflict were more likely in subsequent years to give birth to girls, rather than boys.

“Girls may well be surviving stressful pregnancies that boys can’t survive,” Hamoudi said. “Thus girls are more likely than boys to be born into marriages that were already strained.” Hamoudi and Nobles also make a broader point that reaches beyond the issue of divorce. Population studies typically begin at birth, Hamoudi said. Yet if demographers and other social scientists want to fully understand how family dynamics affect populations, they need to consider the months before birth as well.

“It’s time for population studies to shine a light on the period of pregnancy,” Hamoudi said. “The clock does not start at birth.”

Source: Duke University 

Jul 162014
 

Young teen boy and girl outdoor portrait Teenage boys desire intimacy and sex in the context of a meaningful relationship and value trust in their partnerships, according to researchers at Columbia University’s Mailman School of Public Health. The research provides a snapshot of the development of masculine values in adolescence, an area that has been understudied. Findings are online in the American Journal of Men’s Health.

The researchers studied 33 males who ranged from 14 to 16 years of age to learn more about how their romantic and sexual relationships developed, progressed, and ended. The participants were recruited during routine medical visits at a community adolescent clinic that serves low-income, predominately African-American adolescents. The group’s sexual history began earlier than the national average, putting them at increased risk for sexually transmitted diseases.

Participants were asked open-ended questions about relationships and sex, such as desirable partner characteristics, intimacy, closeness, and trust.

“Prevailing values in our culture suggest adolescent males want sex, not relationships. However, values and behaviors related to sex and relationships are likely more complex than typically portrayed,” said first author David Bell, MD, MPH, assistant professor of Population and Family Health at the Mailman School of Public Health and assistant professor of Pediatrics at Columbia University Medical Center. “In fact, very few of the participants described sex as the main goal of opposite-sex interactions and relationships.”

The study advances an understanding of adolescent males’ early relationships in two significant ways. First, close relationships were important to the participants. Second, they desired intimate and caring relationships, expressed vulnerability and dependence, and placed great importance on trust in relationships.

Few participants described trying to trick or talk a partner into having sex, and few evidenced pride and boastfulness about numbers of sexual conquests. An area of vulnerability expressed by the males was the lack of knowledge about sex and concerns about their own capacity to sexually perform.

These findings starkly contrast with descriptions of older, sexually experienced adolescent males, according to Dr. Bell, in which older adolescents consistently endorse the belief that relationships should be focused around sex, an avoidance of intimacy, and the treatment of females as sex objects.

“Our sample was primarily lower-income African-American adolescent males and the results, while not generalizable, are transferrable to similar populations of adolescent males,” noted Dr. Bell, who is also medical director of NewYork-Presbyterian Hospital’s Family Planning Clinic/Young Men’s Clinic, a provider of primary care services to adolescent and young men. Next steps in the research include analyses of how early adolescent masculine beliefs evolve over time toward more predominant masculine beliefs. These findings can assist clinicians to better address young men’s sexual health needs and incorporate an understanding of adolescents’ developing masculinity into health promotion.

Source: Columbia University’s Mailman School of Public Health

Jul 162014
 

FriendsIf you consider your friends family, you may be on to something. A study from the University of California, San Diego, and Yale University finds that friends who are not biologically related still resemble each other genetically.

Published in the Proceedings of the National Academy of Sciences, the study is coauthored by James Fowler, professor of medical genetics and political science at UC San Diego, and Nicholas Christakis, professor of sociology, evolutionary biology, and medicine at Yale.

“Looking across the whole genome,” Fowler said, “we find that, on average, we are genetically similar to our friends. We have more DNA in common with the people we pick as friends than we do with strangers in the same population.”

The study is a genome-wide analysis of nearly 1.5 million markers of gene variation, and relies on data from the Framingham Heart Study. The Framingham dataset is the largest the authors are aware of that contains both that level of genetic detail and information on who is friends with whom.

The researchers focused on 1,932 unique subjects and compared pairs of unrelated friends against pairs of unrelated strangers. The same people, who were neither kin nor spouses, were used in both types of samples. The only thing that differed between them was their social relationship.

The findings are not, the researchers say, an artifact of people’s tendency to befriend those of similar ethnic backgrounds. The Framingham data is dominated by people of European extraction. While this is a drawback for some research, it may be advantageous to the study here: because all the subjects, friends and not, were drawn from the same population. The researchers also controlled for ancestry, they say, by using the most conservative techniques currently available. The observed genetic go beyond what you would expect to find among people of shared heritage – these results are “net of ancestry,” Fowler said.

Kissing Cousins

How similar are friends? On average, Fowler and Christakis find, friends are as “related” as fourth cousins or people who share great-great-great grandparents. That translates to about 1 percent of our genes.

“One percent may not sound like much to the layperson,” Christakis said, “but to geneticists it is a significant number. And how remarkable: Most people don’t even know who their fourth cousins are! Yet we are somehow, among a myriad of possibilities, managing to select as friends the people who resemble our kin.”

In the study, Fowler and Christakis also develop what they call a “friendship score,” which they can use to predict who will be friends at about the same level of confidence that scientists currently have for predicting, on the basis of genes, a person’s chances of obesity or schizophrenia.

Friends with Benefits

Shared attributes among friends or “functional kinship” can confer a variety of evolutionary advantages. In the simplest terms: If your friend feels cold when you do and builds a fire, you both benefit.

It is also the case that some traits only work if your friend also has them, Fowler said: “The first mutant to speak needed someone else to speak to. The ability is useless if there’s no one who shares it. These types of traits in people are a kind of social network effect.”

Beyond the average similarities across the whole genome, Fowler and Christakis looked in the study at focused sets of genes. They find that friends are most similar in genes affecting the sense of smell. The opposite holds for genes controlling immunity. That is, friends are relatively more dissimilar in their genetic protection against various diseases.

The immunity finding supports what others have recently found in regards to spouses. And there is a fairly straightforward evolutionary advantage to this, Fowler and Christakis say: Having connections to people who are able to withstand different pathogens reduces interpersonal spread. But how it is that we select people for this benefit of immunity? The mechanism still remains unclear.

Also open to debate and also needing further research is why we might be most similar in our olfactory genes. It could be, Fowler said, that our sense of smell draws us to similar environments. It is not hard to imagine that people who like the scent of coffee, for example, hang out at cafes more and so meet and befriend each other. But the researchers suspect there is more to the story than that.

They note, too, that most likely there are several mechanisms, operating both in concert and in parallel, driving us to choose genetically similar friends.

With a Little Help From Our Friends

Perhaps the most intriguing result in the study is that genes that were more similar between friends seem to be evolving faster than other genes. Fowler and Christakis say this may help to explain why human evolution appears to have speeded up over the last 30,000 years, and they suggest that the social environment itself is an evolutionary force.

“The paper also lends support to the view of human beings as ‘metagenomic,’” Christakis said, “not only with respect to the microbes within us but also to the people who surround us. It seems that our fitness depends not only on our own genetic constitutions, but also on the genetic constitutions of our friends.”

Source: University of California – San Diego

Jul 162014
 

msu-student-fitness_lgFor those students looking to bump up their grade point averages during college, the answer may not be spending more time in a library or study hall, but in a gym.

New Michigan State University research shows that students who were members of the recreational sports and fitness centers on MSU’s campus during their freshman and sophomore years had higher GPAs than those who weren’t.

The research also indicated that students with memberships stayed in school longer. An increase of 3.5 percent in two-year retention rates was seen among this group.

“That could equate to about 1,575 people within a student population of 49,000 deciding to move on to a third year of school,” said James Pivarnik, a professor of kinesiology and epidemiology at MSU. “These results provide a compelling argument to universities that a higher student retention rate could be enhanced just by having adequate recreational and fitness facilities for students.”

The study, led by Pivarnik and MSU doctoral student Samantha Danbert in the Department of Kinesiology, can be found in the most recent issue of the Recreational Sports Journal.

The research supports previous theories suggesting that by creating an environment that connects students to an institution, in this case a university recreational facility, an increase in academic success and retention can occur.

During the project, Pivarnik’s team analyzed data from a sample of freshmen and sophomores, totaling 4,843 students, and compared the GPAs of those who purchased a fitness facility membership and those who did not. Results showed that after four consecutive semesters, the students with memberships obtained higher cumulative GPAs. They also had more credits completed by the end of their first year in college.

“We found that these students’ cumulative GPAs were 0.13 points higher,” Pivarnik said. “Although this number may not appear to be significant, in the end, that amount could mean the difference to those students on the cusp of getting into graduate school or even advancing to the next academic year.”

Pivarnik noted that 74 percent of those with memberships successfully gained their sophomore status while only 60 percent reached that goal in the nonmember group.

“The results of this study are important because not only are we retaining more students, but we’re retaining those that have higher GPAs which is good for everyone,” Pivarnik said.

Other researchers involved in the study included Richard McNeil, MSU’s director of recreational sports and fitness services, and Ira Washington, a statistics specialist also at the university.

Source: Michigan State

Jul 152014
 

The area of the brain that plays a primary role in emotional learning and the acquisition of fear – the amygdala – may hold the key to who is most vulnerable to post-traumatic stress disorder.

Researchers at the University of Washington, Boston Children’s Hospital, Harvard Medical School and Boston University collaborated on a unique opportunity to study whether patterns of brain activity predict teenagers’ response to a terrorist attack.

The team had already performed brain scans on Boston-area adolescents for a study on childhood trauma. Then in April 2013 two bombs went off at the finish line of the Boston Marathon, killing three people and injuring hundreds more. Even people who were nowhere near the bombing reported distress about the attack and the days-long manhunt for the suspects.

So, one month after the attack, Katie McLaughlin, then at Boston Children’s Hospital and Harvard Medical School and now an assistant professor of psychology at the UW; co-author Margaret Sheridan, of Boston Children’s Hospital and Harvard Medical School; and their fellow researchers sent online surveys to teenagers who had previously participated in studies to assess PTSD symptoms related to the attack.

By using functional Magnetic Resonance Imaging scans from before the attack and survey data from after, the researchers found that heightened amygdala reaction to negative emotional stimuli was a risk factor for later developing symptoms of PTSD.

The research study was published July 3 in the journal Depression and Anxiety.

“The amygdala responds to both negative and positive stimuli, but it’s particularly attuned to identifying potential threats in the environment,” said McLaughlin, the study’s first author. “In the current study of adolescents the more their amygdala responded to negative images, the more likely they were to have symptoms of PTSD following the terrorist attacks.”

The brain scans were conducted during the year prior to the bombing. At that time, the teens were evaluated for their responses to emotional stimuli by viewing neutral and negative images. Neutral images included items such as a chair or button. Negative images showed people who were sad, fighting or threatening someone else. Participants rated the degree of emotion they felt while looking at each image. The MRIs measured whether blood flow increased to the amygdala and the hippocampus when viewing negative images as compared to neutral images.

In the follow-up survey the teens were asked whether they were at the finish line during the bombing, how much media exposure they had after the attack, whether they were part of the lockdown at home or school while authorities searched for the suspects, and how their parents responded to the incident. They also were asked about specific PTSD symptoms, such as how often they had trouble concentrating and whether they kept thinking about the bombing when they tried not to.

Researchers found a significant association between amygdala activation while viewing negative images and whether the teens developed PTSD symptoms after the bombing.

McLaughlin said a number of previous studies have shown that people with PTSD had heightened amygdala responses to negative emotions, but researchers didn’t know whether that came before or after the trauma.

“It’s often really difficult to collect neurobiological markers before a traumatic event has occurred,” she said. By scanning the adolescents’ brains before the bombing, she and her fellow researchers were able to show that “amygdala reactivity before a traumatic event predicts your response to that traumatic event.”

While two-thirds of Americans will be exposed to some kind of traumatic event during their lifetime, most, fortunately, will not develop PTSD.

“The more we understand the underlying neurobiological systems that shape reactions to traumatic events, the closer we move to understanding a person’s increased vulnerability to them,” McLaughlin said. “That could help us develop early interventions to help people who might develop PTSD later.”

Other co-authors are Andrea Duys, of UW; Daniel Busso and Sonia Alves at Harvard; and Jennifer Greif Green at Boston University. The research was funded by the National Institutes of Health.

Source: University of Washington

Jul 152014
 

75988_webMore than 140 years ago, Charles Darwin noticed something peculiar about domesticated mammals. Compared to their wild ancestors, domestic species are more tame, and they also tend to display a suite of other characteristic features, including floppier ears, patches of white fur, and more juvenile faces with smaller jaws. Since Darwin’s observations, the explanation for this pattern has proved elusive, but now, in a Perspectives article published in the journal GENETICS, a new hypothesis has been proposed that could explain why breeding for tameness causes changes in such diverse traits.

The underlying link between these features could be the group of embryonic stem cells called the neural crest, suggest the authors. Although this proposal has not yet been tested, it is the first unified hypothesis that connects several components of the “domestication syndrome.” It not only applies to mammals like dogs, foxes, pigs, horses, sheep and rabbits, but it may even explain similar changes in domesticated birds and fish.

“Because Darwin made his observations just as the science of genetics was beginning, the domestication syndrome is one of the oldest problems in the field. So it was tremendously exciting when we realized that the neural crest hypothesis neatly ties together this hodge-podge of traits,” says Adam Wilkins, from the Humboldt University of Berlin. Wilkins is an editor at GENETICS and one of the paper’s authors.

Neural crest cells are formed near the developing spinal cord of early vertebrate embryos. As the embryo matures, the cells migrate to different parts of the body and give rise to many tissue types. These tissues include pigment cells and parts of the skull, jaws, teeth, and ears—as well as the adrenal glands, which are the center of the “fight-or-flight” response. Neural crest cells also indirectly affect brain development.

In the hypothesis proposed by Wilkins and co-authors Richard Wrangham of Harvard University and Tecumseh Fitch of the University of Vienna, domesticated mammals may show impaired development or migration of neural crest cells compared to their wild ancestors.

“When humans bred these animals for tameness, they may have inadvertently selected those with mild neural crest deficits, resulting in smaller or slow-maturing adrenal glands,” Wilkins says. “So, these animals were less fearful.”

But the neural crest influences more than adrenal glands. Among other effects, neural crest deficits can cause depigmentation in some areas of skin (e.g. white patches), malformed ear cartilage, tooth anomalies, and jaw development changes, all of which are seen in the domestication syndrome. The authors also suggest that the reduced forebrain size of most domestic mammals could be an indirect effect of neural crest changes, because a chemical signal sent by these cells is critical for proper brain development.

“This interesting idea based in developmental biology brings us closer to solving a riddle that’s been with us a long time. It provides a unifying hypothesis to test and brings valuable insight into the biology of domestication,” says Mark Johnston, Editor-in-Chief of GENETICS.

Tests of the neural crest hypothesis may not be far off, as other scientists are rapidly mapping the genes that have been altered by domestication in the rat, fox, and dog. The hypothesis predicts that some of these genes will influence neural crest cell biology.

If so, we will have a much deeper understanding of the biology underlying a significant evolutionary event, Wilkins says. “Animal domestication was a crucial step in the development of human civilizations. Without these animals, it’s hard to imagine that human societies would have thrived in the way they have.”

Source: Genetics Society of America

Jul 152014
 

In officeModern office workers are expected to multitask regularly, often juggling multiple projects and priorities over the course of a day. Studies have shown that the typical employee in an office environment is interrupted up to six times per hour, but how does that impact the finished product? New research published in Human Factors evaluates how ongoing interruptions can negatively affect the quality of work.

“People don’t realize how disruptive interruptions can be,” said Cyrus Foroughi, coauthor of “Do Interruptions Affect Quality of Work?” and a PhD candidate at George Mason University’s human factors and applied cognition program. “There is value in determining whether interruptions affect the quality of the tasks that many people perform regularly, such as writing essays or reports.”

Foroughi, with coauthors Nicole Werner, Erik Nelson, and Deborah Boehm-Davis, designed a study assessing how varying levels of interruption affected writing quality in an essay project. Two groups of participants were given time to outline and write an essay on an assigned topic. One group was interrupted multiple times with an unrelated task, and a control group had no interruptions. Independent graders scored the finished essays on a numbered scale.

The researchers found significantly lower quality in essays completed by the participants who were interrupted during the outline and writing phases than in essays of those who were not interrupted. In addition, those participants who were interrupted during the writing phase wrote considerably fewer words.

“Interruption can cause a noticeable decrement in the quality of work, so it’s important to take steps to reduce the number of external interruptions we encounter daily,” said Foroughi. “For example, turn off your cell phone and disable notifications such as e-mail while trying to complete an important task.”

Source: Human Factors and Ergonomics Society

Jul 152014
 

After a concussion, teens who are sensitive to light or noise may be more likely to also have emotional symptoms such as anxiety, according to a study released today that will be presented at The Sports Concussion Conference in Chicago, July 11 to 13, 2014, hosted by the American Academy of Neurology, the world’s leading authority on diagnosing and managing sports concussion. The conference will feature the latest scientific advances in diagnosing and treating sports concussion from leading experts in the field.

The symptoms after a concussion can vary widely from person to person. Symptoms can include physical, emotional and cognitive difficulties.

“While most people recover from a concussion within a week, a number of factors affect people’s recovery, and studies have shown that teenage athletes may take up to seven to 10 days longer to recover than older athletes,” said study author Lisa M. Koehl, MS, and Dong (Dan) Y. Han, PsyD, of the University of Kentucky in Lexington.

The study involved 37 athletes age 12 to 17 who had persisting symptoms for an average of 37 days following a concussion. Participants were excluded if they had a previous history of psychological issues. One group of 22 teens had emotional symptoms such as irritability, aggression, anxiety, depression, apathy, frequent mood changes or excessive emotional reactions after the concussion. The second group of 15 teens did not have emotional symptoms. There were no differences between the two groups in factors such as what percentage experienced loss of consciousness or amnesia, indicating that the groups were likely comparable in the level of severity of concussion.

The study found that of the 22 teens who had emotional symptoms, five teens (23 percent) were sensitive to light while three teens (14 percent) were sensitive to noise. In comparison, of the 15 teens without emotional symptoms only two teens (13 percent) were sensitive to light and no teens were sensitive to noise.

The number of concussions experienced and whether teens also had headaches or nausea were not related to whether they also had emotional symptoms. Researchers also found that having a family history of psychiatric problems did not make teens any more or less likely to have emotional symptoms after a concussion.

Teens who had anxiety were 55 percent more likely to self-report attention difficulties than those without anxiety, while teens with irritability/aggression were 35 percent more likely to self-report problems with attention than teens without irritability. The authors noted that the findings are preliminary with small samples and stressed the importance of replicating this study with a larger sample size.

“Identifying factors such as these that may exacerbate issues teens experience after concussion may help in planning for the appropriate treatment and in making decisions about when to return to play and what accommodations are needed at school for these athletes,” Koehl and Han said.

Source: American Academy of Neurology

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